Rheostat.



PATENTED MAY 26, 1908.

SPA. LEONARD.

RHEOSTAT. ABPLIGATION FILED Hum 17, 1997.

3 SHEETS-SHEET l.

No. 888,517. PATENTED MAY 26. 1908.

' s. A. LEONARD.

RHEOSTAT.

APPLICATION FILED JUNE 17 1907.

3 SHEETS-SHEET 2.

- INVENTOR.

} 'ge ihA Leonard Z MV I VITNESSES: 9| I dim mm A TTORNE Y,5

PATENTED MAY 26, 1908.

s. A. LEONARD 'RHEOSTAT. APPLICATION FILED JUNE 17,1907

3 SHEETS-SHEET 3.

INVENTOR.

756th AdLeonavd A TTORNE m.

UNITED STATES PATENT OFFIG SETH A. LEONARD, Oli CLEVELAND, OHIO.

mrabsTA'r.

Application filed June 17, 1907. Serial No. 379,300.

, invention consists in the construction and arstructed with relativelylow ampere conductive capacities and for relativel high voltages, eachunit bein capable 0' taking the entire voltage on the ine.

The units of each set may have different conductive capacities or valuesfrom theother sets, or all maybe equal, dependent'upon the work calledfor.

In rheostats ordinarily, the smallest amount of'wire is in circuit whenthe current is heaviest and which puts a heavy burden on that portion ofthe rheostat in use, especially as the cross sectional area of the wireis always fixed and invariable, whereas in my invention the opposite istrue, because I place the greatest amount of wire in circuit 0th incross section and length when thegreatest amountofiicurrent-jis flowing,and

thereby rovide for ncreased radiating surifaces an Increase 1 currentcarrying capac ty when most needed? Burning out of any commission, and tis is one zi'dvantage in having a large number of un s working in}multiple whenoperating under he'avy'conditions. However, each unit isdesigned to carry the extreme voltage on the'line and burning outthereof is reduced to a minimum. (,ompactness and economy in.construction are other features in favor of my device, es-

pecial ly when capacity and wide range of use is taken intoconsideration. 'For storage battery work, it has a range hitherto deemedimpossible, as the smallest s arking battery or the largest sizedautomobi e-truck battery may be charged or discharged with one andthesame device. The rheostat shown in the Specification of LettersPatent.

open work frame built u plates S in an particu Patented May 26, 1908.

- Fig. 2 is a sectional view thereof on line 22,

Fig. 1. Fig. 3 is a cross sectional view through the central portion ofthe rheostat, and Fig. 4 is a plan view and section on line 44, Fi 3.Fig. 5 is an enlarged face view of one of the resistance coil units, andFig. 6 is a sectional elevation thereof. Fig 7 is a diagrammatic view ofthe elementary parts of the rheostat and their electrical. connections.i

i In detail, my invention comprises 'a-rigid of vertical'corner pieces 3of angle iron rigi ly united at difl'erent elevations by front and rearcross rods 4, and which rods provide supports forthe ends ofparallelbars5 located at each sideand in; the. center of the frame. Bars 5 havea series of side lugs 6 or walledslots 7 spaced apart thereon from endto'end which provlde lateral supports for flat asbestos, and w iehplates are urther sup lates 8 of ported-and held in place bylongitudinal strips 9 screwed or otherwise fastened to either the toporbottom edge'of bars 5. Double rows orsets of such asbestos plates 8jare th us supported at equaldi'stances apart H from front to rear of'the frame'and at two one: unit willfnot affect f the other units or lacethe rheostat out of different elevations on said frame, and u on removalof pairs of stri s 9, any one or a of.

ar section may be removed or rep aced.

Each plate 8 is notched or slotted at opposite edges, top and 'bottom,to' provide'supporting portions 9" for resistance coil 10 which is woundspirally upon said plate in a continuous manner, beginning at one sideand top at a binding postfll and then pass-' ing down tothe bottom wherea loop '12 of the coil is slip ed over portion 9 before passing up ontfie o posite side of the plate to make a similar lbop attachment-at thetop", and thence downward and up again in like manner and in zigzagformation until the end is reached at a second binding post l3 at'theother end of plate 8. In other words, resistance coil 10 is a helicalwire coil wound spirally as-a continuous body upon and around flat plate8 from end to end and with the windings spaced apart and out of contact,and wherever the coil passes over the edges of the hat plate a loop 12of the coil is engaged with a projecting portion 9 to hold and ii); eachwinding against lateral and longitudinal movement. all wound in asimilar manner and are of uniform size, but as shown in the drawingsresistance coils it) are alike only in part, being divided into threesets of coils 10 in which the units thereof are designated by (I, b and,c, respectively, see Fig. 7. The amount of wire in units a is much lessthan in units 7), and the same is true comparatively of units (1 and c,and constructively, the difi'erence lies in the diameters of the coilsand in the gage of wire used, units (1. having a conductive capacity ofone ampere of current each, units 1) two amperes, and units 0 threeamperes. However, it must be understood that I glo not wish to limitmyself to the definite number or capacity of the dii'l'erent units orsets of units shown, as diil'erent requirements and conditions may bereadily met by' diil'erent combinations and arrangements of the units;To further this end,

said units are interchangeable and remov ably and rcplaceably securedwithin the main frame.

'Now, rel crring'to the switch mechanism for the rhcostat, a rotaryswitch 15 is I mounted upon a projecting. stud or bolt 16 secured toinsulating base plate 17 located upon posts 3 at the front of the frame.Said switch is ol" semicircular outline and is providod with a series ofspring pressed contact pins 18, one for each contact segment 19 arrangedin a. semi-circle on base plate 17 and numbering forty all told. Switch15 may be rotatcil either to the right or to the left to make initialcontact with either contact segment 10 at. the end of the semi-circle orthe succeeding segments nextin line. Contact segments in are insulatedone from another, and have separate electrical connections or wires 20leading to the binding posts ll of their corresponding resistance coilIt), and switch 1:) has a single electrical lead or wire 21 connectedwith line terminal 22 on base plate 1?. ("oils 10 are connected in multido and to that end, have a return wire 23 rom their respective bindingposts 13 on each plate 18 leading to line terminal individually with thelirst set of coils or units (1 of one ampere each, and that the middleseries of segments, fourteen in number, connect with the second set ofcoils or units 1) of two amperes each; and again, that the right Plates8 are .1 end series, also fourteen in number, connect twelve, inclusive,and then by twos to forty, and then by threes to eighty-two. Readingfrom the right to the left, or reversely to he former reading, thevalues sum up ditl'erently and are cumulatively reckoned in threes forthe lirst fourteen segments, and p then by twos, and linally by ones.'lhus,:the current may be gradually va'ried in diil'erent l proportions,dependent upon whether switch 15 is rotated to the left or the rightfrom starting position, and a. relatively large and ilexiblc range inamperage is thus obtained by a single switch and a limited number ofworking parts.

, The resistance coils may all be alike, say 01 five ampere conductingcapacities each, and

l accumulate in single amperes, from one to i connected in multiple togradually vary an electrical current under high voltage, and 1 havefound that in this connection I can pro-. duce ell'ccts and obtainresults hitherto considered impracticable in a commercial rheostat,especially in theatrical 'work' and in connection with moving picturemachines.

What l claim is:-

1. ln rheostats, a series of resistance units of the same conductivecapacities, combined with a. series of resistance units of diil'erentconductive -apacities, all of said units being electrically connected inparallel. and a switch for all said units adapted to switch each unit inparallel and successively and from one series to another.

2. in rheostats, separate sets of resistance units electricallyconnected, the respective sets having units of dil'l'erent conductiveca.- pacities and the units ol" each set having the same conductivecapacities, and all said units having relatively low ampere conductingcapacities at rclativelv high voltage, in ii'ombination with a switchelectrically onnected in parallel with every unit in said res )ectivcsets and arranged to place part or all of said units in parallelcircuit. I

3. A rheostat. compri"ng separate sets of resistance units electricallyconnected and havingrelatively greater conductive capaci tics increasingsuccessively from one set to another, in combination with a rotatingswitch electric-ally connectml in parallel with each unit of each setand arranged to switch in said units from the first to the lastsuccessively until all said units are. in circuit in parallel. v

4. In rheostats, a series of resistance units electrically connected inparallel and divided into sets of different conductive capacities withlike units in each set, in combination with a rotary switch adapted tobe either continiiously rotated in one direction to place anypredetermined number thereof may be i units of the same individualcapacity, and

tinuin' folds of equal length and on opposite sides t ereof.

l equal length on opposite sides thereof.

body' to hold and fix each winding against units mounted in parallelrows thereon and vertical standards, and a series of parallellsupporting bars mounted thereon at different elevations and providedwith grooved faces, .45

vary the cumulative effect of said units.

units of variable individual conductive capac- .of'- resistance unitsremovably mounted thereonand comprising separate insulating 1.5 p

sulating materia and helical resi'stance coils W0u'nd spirally aboutsaid plates in a congprising a flat insulating plate having er e =1projections and a helical resistance coil Wound spirally thereon in acontinuous body and having loops of said coil looped with said I 9. Inrheostats, a main frame having a sesee-,srr

each unit in each set successively and cumulatively in circuit orreversely rotated to 5. In rheostats, a series of resistance ityelectrically connected inparallel in sets of said sets of unitssuccessively arranged in cumulative value, and a switch therefor adaptedto throw either the lowest or the highest sets of units initially incircuit.

6. In rheostats, a main frame and a series lates having a spirally woundresistance coil wound spirally around said plate in con- ;17'. Inrheostats,- a main frame and a series of resistance units supportedthereby, said units comprisin separate flat plates of in- {tinuous coilbody with parallel portions of 8. A resistance unit for rheostatscomedge projections'at each winding of the coil lateral andlongitudinalmovement.

ries of horizontal bars Harallelly arranged at different elevations, an

a series of resistance apart from one another, said units comprisingflat plates and having helical resistance coils secured on oppositesides thereof.

' '10. In rheostats, a main frame comprisim in'combination withresistance units com-1 prisin flat plates adapted to be removably seatewithin said grooved faces and helical coils spirally wound around saidplatesand having terminal binding posts for making detachable electricalconnections for each unit.

11. In rheostats, a main frame having ver tical corner pieces and crossrods connecting the same and parallel bars supported at differentelevations by said rods, in combinaor reversely for varying results.

. 13. In rheostats, a series of separate, re-

sistance coils of relatively low ampere 65hducting capacities arrangedin sets of different unitary values, in combination with switchmechanism electrically connecting said coils in parallel and comprisinga semicircular series of contacts, one for each coil, and a rotatableswitch having a semi-circular contact portion adapted to successivelyswitch in all of said coils in parallel by rotating the same in eitherdirection and whereby the cumulative efiect of the current to beswitched in may be varied dependent upon the initial direction ofrotation of the said switch.

In testimony whereof I sign this specification in the presence of twowitnesses.

SETH A. LEONARD.

Witnesses: R. B. Mosnn,

Frsnnn.

